This invention relates to a pull-on disposable diaper.
Japanese Patent Application Publication No. 1975-33044A discloses a foldup-type disposable diaper 201 as shown in FIG. 8 of the accompanying drawings. This diaper 201 is composed of a liquid-absorbent pad, a liquid-pervious inner sheet 222 and a liquid-impervious outer sheet 223 so as to present a rectangle and this rectangle is then folded along a transversal 210a orthogonal to long sides of the rectangle in two halves in a longitudinal direction. Simultaneously, the rectangle is tucked from its transversely opposite side edges inwardly of the diaper, more specifically, toward a middle point of the transversal 210a so as to form pockets 218. Surface sections of the sheet 223 facing each other as the rectangle is tucked inward in this manner are partially bonded to each other in order to prevent the respective pockets 218 might get out of initial shapes thereof even after the diaper has been developed to put the diaper on a wearer's body. The diaper arranged in such manner is effective to avoid leakage of body fluids regardless of its rectangular shape because a region of the diaper destined to cover the wearer's crotch region is sufficiently narrow to be placed closely against the wearer's crotch.
Japanese Utility Model Application Publication No. 1972-36734A discloses a foldup-type diaper made from a rectangular strip. The diaper is tucked inward from its transversely opposite edges in a longitudinally middle zone of the diaper. The crotch region of the diaper obtained in this manner has its width sufficiently reduced to be placed closely against the wearer's crotch and thereby to alleviate an anxiety of sideways urine leakage.
The diaper disclosed by Japanese Patent Application Publication No. 1975-33044A intends to prevent the diaper from getting out of its initial shape by partially bonding together the surface sections opposed to each other as the diaper is folded and tucked. However, such bonding may obstruct the diaper to be flatly developed and retard operation of putting the diaper on the wearer's body. While this conventional diaper has advantageous effects that the crotch region is folded and tucked inward so as to reduce a width of the crotch region and thereby an anxiety that the crotch region might uncomfortably compress the wearer's crotch, there is no guarantee that discharged body fluids correctly flow in an area within the crotch region folded and tucked inward. Consequently, body fluids are apt to leak sideways from the diaper.
The diaper disclosed in the above-cited Japanese Utility Model Application Publication No. 1972-36734A is accompanied with an inconvenience that the crotch region folded and tucked in this manner is apt to get out of its folded and tucked state as the diaper is put on the wearer's body.